Transmission



0. K. KELLEY TRANSMISSION Jan. 15, 1963 8 Sheets-Sheet 1 Original Filed Oct. 27, 1952 Vi Ts m i /zy A TTOR/VEY 0. K. KELLEY TRANSMISSION Jan. 15, 1963 8 Sheets-Sheet 2 Original Filed Oct. 27, 1952 INVENTOR. Lfl LB K. KELLEY ATTORNEYJ.

Jan. 15, 1963 0. K. KELLEY 3,073,183

} TRANSMISSION Original Filed Oct. 27, 1952 8 Sheets-Sheet 3 INVENTOR. 0L! 1 52 K /(ELLEY I @Mw aZQam/ WJ/W A TTOENE Y5 0. K. KELLEY TRANSMISSION Jan. 15, 1963 8 Sheets-Sheet 4 Original Filed Oct. 27, 1952 INVENTOR. OLA/2 K KELLEY BY W ATTOPNEKSI 0. K. KELLEY TRANSMISSION Jan. 15, 1963 Original Filed Oct. 27, 1952 8 Sheets-Sheet 5 0. K. KELLEY Jan. 15, 1963 TRANSMISSION 8 Sheets-Sheet 6 Original Filed Oct. 27, 1952 INVENTOR. OLIVER K KELLEY ATTORNEYS.

O. K. KELLEY Jan. 15, 1963 TRANSMISSION 8 SheetsSheet 7 Original Filed Oct. 27. 1952 k. QW

0. K. KELLEY TRANSMISSION Jan. 15, 1963 8 Sheets-Sheet 8 NMN onver' K: are 1',

This invention relates to automatic transmissions for automotive vehicles.v The specification which follows is a continuation offmy' application, Serial No. 317,895 filed October 27, 1 952.

The transmission which is disclosed herein, as one example of the inventiomis suitable for transmitting power fol-driving vehicles of the track laying type, for military or other purposes. In this respect the transmission disclosed herein is of a cross drive construction in that the torque output shaft extends crosswise of the vehicle for driving sprocket elements over which the endless tracks of the vehicle operate, but certain features of the invention areuseful in any type of vehicle.

The objects of the invention include an arrangement for cooling brakes of the vehicle, which brakes are also employed in the steering of a track, laying vehicle, wherein a cooling and lubricating oil is pumped over the brakes when and only when they :are in use. operation, the oil isnot maintained under pressure with resultant economy of operation and the saving of Wear on thepump's and related parts.

The objects include a control system fora vehicle,

and particularly one of the track laying type wherein, through the means of common control elements, an operat'o'r may manipulate brakes for the vehicle, and control power output clutches of the vehicle. In this way the vehicle may be controlled and steered easily. The objects also include an arrangement of cone clutches in the transmission for engaging and releasing friction elements to change from one speed ratio to another, which cone elements are arranged so that one provides reaction for the other and so cushions the shift. This construction is applicable to'a. transmission for any purpose. Some of the gearing of the transmission requires efficient lubrication andcooling and the invention provides a construction for delivering cooling and lubricant oil to certain of the main driving gears.

The transmission embodies a combination including a fiuidtorque converter with speed change gearing and a lock-up clutchfor the torque converter, which clutch, if

Thus, in normal is is engaged for transmitting torque, becomes disengaged during a change of speed ratio, after which the clutch re -engages. Thus, in making a speed ratio change, 'the torque is transmitted through the fluid torque converter which softens the shift.

Other objects include a hydraulic control system in" which hydraulic medium is pumped under pressure The discharge line from through "the torque converter. I the torque converter is controlled by the pressure of the inlet line for the torque converter and thus excessive pressure in the torque converter (indicated by the pressure in the inlet line of the torque converter) cannot be built up. Moreover, the hydraulic system includes a governor which reduces main line, or pump, pressure at normal vehicle speeds, which may be termed relatively high speed. Thus, in normal operation a relatively low pressure is maintained on the high side of the pump with resultant saving in power as well as wear on theparts.

F136. 1 is a schematic representation of a transmission and final drive embodying one form of the invention, the transmission being shown .as one-half ofa longitudinal section which is-symmetrical about its axis,

,FIG..2 is a side elevation of one form of actual sti'uC- ture of the transmission housing showing some of the inner structural parts in dotted lines and illustrating external control features,

FIG. 3 is a. detailed view partly in section illustrating a manual control for brakes, v r

FIG. 4 is an exploded perspective illustrating brake actuating structure,

FIG. 5 is an axial sectionalview of one form of actualv structure of the fluidtorqueconverter, the lock-upclutch and other related parts taken substantially on line 5-5 of FIG.

. FIG. 6 is a sectionalview, taken through the part of the transmission l-ocatedto the right of that shown in FIG. 5,

showing the structure of the main driving gears and planetary change-speed gearing and the controlling clutches therefor and taken substantially on line. 6-6 of FIG, 2, 7

FIG. 7 is a view illustrating the structure of the cross drive shaft showing thev controlling clutch arrangement at one output end of the drive shaft and taken substantially. on line 7+7 of FIG. 2,

FIG. 8 is a view showing the braking and steering controlarrangement to be-manipulated by an operator,

FIG; 9 is a detailed view partly in section of the brake band for establishing; second speed drive,

FIG., 10 is anenlarged sectional view taken substantially on line iii-w of PEG. 2 illustrating part of the ground brake construction and'showing the valving arrangement associated therewith, j 5

FIG. 11 is a diagrammatic view illustrating part of the hydraulic system, j

FIG. 12 is a diagram of the hydraulic control system illustrating the structureof some of the mechanical parts and valves, and;

FIG. 13 is a view of diagrammatic nature showing the structure of a centrifugal governor valve. v

,Asshown in FIG. l the transmission has a torque converter including an impellerS driven by an engine 2, a

turbine iii and reaction elements 14 and 15. The turbine ltl rot ates a converter output shaft 12 which can be connected tothe impeller 5 by a lock-up clutch 27-2 8 when it is desired to drive the shaft 12 directly from the engine. The converter outputshaft is the input shaftv for a planetary change-speed transmission including two input sun gears 44 and 70 driven by the shaft 12. The sun gear 7th meshes with planets 71 mounted on a carrier 73-75 and meshing with a reaction ring gear 65 which may be held by a brake 95-97 to drive the carrier forward at low speed, The carrier is connected to output shaft 76. The sun gear 4t meshes with planets 41 mounted on a carrier 42-63 and meshing with a reaction ring gear. 43v whichcan be held by a brake 46 to drive the carrier 42 63 forward when thebrake 95-97 is released. This drives the ring gear 65 forward and thereby drives the carrier 73-75 forward fasterthan when the ring gear 65 is 'held,'-because sun gear 7% is also rotating. This efiectssccond speed. Third speed, or direct drive throughthe gearing, is established by locking up the planetary gearset t tl 4-2v i3 by a clutch 51 which can connect ring gearefi tosun gearfiiti when it is set by a piston 48 in a hydraulic cylinder 47.

These and other objects will be fully appreciated as the The drawings show Reverse is established by a' third planetary gearset including an input sun gear 68; driven by the ring gear. 65 and meshing with planets 86 mounted on a carrier 82-34 connected to the output shaft, and also meshing with a reverse reactionring gear 81 which can be held by reverse brake 1651-198. When all other friction torqueestablishing devices are released and the reverse brake verse rotation of ring gear 65 "rotates sun gear68 backward, which, when ring gear 81 is held, rotates carrier 825-84 backward to drive output shaft 76 backward.

TA bevelfdrive'. gear 88is keyedto output shaft 76 and meshes with bevel gear 89 keyed to cross shaft 90 which at each end has a'final drive clutch 133 which can be engaged to rotate a final drive shaft 136. The clutches can be operated independently and the final 'drive shafts 136 can be separately or simultaneously retarded by brakes 150. The shafts 156 may drive tracks, and the vehicle can be steered by various-combinations of clutching and braking, as will be explained.

. The transmission may be contained in a suitable housing 1 secured to an engine, the shaft of which is shown at'2 with fly wheel .3. The impeller 5 of 'a fluid torque converter is secured to the flywheel at 6. The part of the impeller remote from the flywheel is journalled on a bearing 7 and it has secured thereto a gear 8 for driving pumps for the control system, as will be explained. The

driven member or turbine of the torque converter 10 is.

mounted upon a flange 11 secured to the converter output'shaft which is the gearing input shaft 12 which has a passageway 13 therein.

The torque converter is completed by two reaction elements or stators 14 and 15 each supported on a fixed ground member 16 by one-way brakes, the ground member 16 being secured to a fixed sleeve 20. The elements the torus chamberare impeller blades or vanes 21, turbine blades22, and reaction blades 23 and 24. Hydraulic medium such as oil is supplied to the torus chamber.

The lock up clutch has a clutch'disc 27 secured to the turbine flange 11 and positioned between a driving member 28 and a piston 29 which serves as a pressure plate. The piston is disposed within a cylinder 36 formed in a front cover 31 which completes the container constituting the torque converter and is secured to the impeller. The

strut 57. The lever 54 is actuated by a rod 58 connected by a link 59 to a piston 68 in a cylinder 61. It will be seen that introduction of hydraulic medium under pressure into the'cylinder 61 will swing the lever counterclockwise as FIG. 8 is viewed, thus contracting the band 46 and causing it to engage brake drum 45.

The carrier for the planetpinions 41 includes a flange 63 journalled on a bearing 64 and splined toa low ratio ring gear 65, at 66. An opposite and similar flange 67 is'splined to gear 65 and to a reverse sun gear 68 mounted V on a bearing A low ratio sun gear 76 is keyed to the converter out put shaft and its teeth mesh with planetary pinions 71, the teeth of which mesh with those of the low ratio reaction ring gear 65' The pinions 71 are mounted on shafts "73 in a carrier constituted by a cheek 74,and a flange 75, which latter is splined to .a transmission output shaft 76. V I v The reverse sun gear 68 has its teeth meshing with the teeth of planetary pinions 89 and the teeth of thepinions mesh with those of a reverse reaction ring gear 81. The pinions 88 are journalled on shafts 82 mounted in a check 83 and a carrier flange v84, splined to the output shaft 76, carried in a bearing 85 and a bearing 86 (FIG. 4) and secured to a bevelled gear 88 driving the bevel gear 89 on a cross shaft 94?. Advantageously the gears 88 and 89 are of the hypoid type and require eflicient lubrication and cooling. The cross shaft 90 and the shaft 76 are output shafts relative to the entire transmission. It convenient to identify the shaft 12 and the sleeve 76 as'input and output members, respectively, of the of the torque converter thus form a torus chamber and in piston is rotated with the cover 31 but can shift axially in the cylinder. Driving pins for the piston are indicated at 32. A bearing 33 is positioned between the stator support 16 and the hub part of turbine flange 11; the converter output shaft 12 has a counter-bored endportion for receiving acentral extension 34 of the piston 29, the hollow partforming a passageway 35 which communicates with the bore 13 so that oil can pass into the cylinder 30 to actuate the piston 29, urging it to the right as FIG. 4 is viewed, to engage the clutch.

The planetary gearing associated with the converter output shaft 12 is illustrated 'in FIG. 5. There is an intermediate ratio sun gear 40 mounted on the shaft 12 and meshing with planet gears 41, each mounted upona shaft 42 and meshing with a reaction ring gear 43. Secured to the ring gear 43 is intermediate ratio brake drum 45, which can be held fast by a brake band 46.

Also secured to the ring gear 43 is a cylinder 47 containing a piston 48. There is a clutch hub 58 spaced from the piston 48 and splined to the shaft 12..

A third speed or planetary lock-up clutch 51 has driven discs splined to the member and driving discs secured to the hub '59. This clutch is engaged to lock-up the intermediate ratio gearset when oil under pressure is introduced into the cylinder 47 to urge the piston 48 to the left as FIG. 5 is viewed. Coil springs 52 normally hold the clutch 51 disengaged.

The brake drum 45 may be held by the band 46 by means shown in FIG. 8. expanded by a spring 53; A lever 54 is mounted on a fixed pivot which is carried by the case. Links 56 are also mounted on the pivot 55 and support the fixed end of the band 47. The lever 54 sets the band by a The band is held normally.

gearing.

The low ratio ring gear has oppositely tapered conical brake surfaces. A brake member 95 splined as at 96to the housing cooperates with one cone' surface. A brake member 97 splined to the housing as at 98 cooperates with the other cone face. These two members are normally held in proper relationship with the ring gear 65 by holding rings both indicated at 100. The two braking elements 95 and 97 are normally held separated by coil springs 161 of which there may be several spaced circumferentially about. A low ratio establishing piston 192. is disposed in a cylinder 103'for actuating the brake element 95.

shifted to the right causing the other cone surface to engage the brake member 108, the brake member 168 "being Similar braking elements 107 and 108are associated with the oppositely co-ned surfaces of the .reverse ring gear 81. These elements are splined to the housing as at 169 and 110, are held normally separated by springs 111 and areretained in position by retaining elements 112. A reverse-establishing piston 115 in cylinder 116 is arranged to operate the clutch element 107. The piston 182 and the brake element are associated by thrust pieces 118 and the piston'115is associated with the brake element 107 by thrust pieces 119.

When oil under pressure is. delivered to the cylinder 103 the piston 102 shiftsto the left'as FIG. 5 is viewed. Thiscauses the brake element 95 to engage one cone surface of the ring gear 65. Following this engagement theclutch element 95 and the ring gear 65 continue shiftmg to the left until the other cone surface engages the cone face of the brake element 97. The brake element 97 is backed up by an abutment member 120 so that it cannot shiftto the left. Similarly, when oil under pres-- sure is delivered to cylinder 116 piston 'shifts to the right causing the brake element 187 to engage one cone surface of the ring gear 81. Then the ring gear 81 is backed up by the abutment member 120.

The result of this is that the ring gear 65 and the ring gear 81 may be engaged by the brake elements and held against rotation. In the action of engagement one of the brake members, for example, the clutch member 95, engages the ring gear 65 and the brake member and ring gear shift to the left, as FIG. 5 is viewed, until the ring gear comes into engagement with the brake member 17. The brake 97 provides the reaction necessary for complete engagement of the brake members 95 and 97 with the ring gear 65.

For second speed gear drive the ring gear 43 is held stationary by brake band 46. The sun gear itt'rotates in the same sense and speedas the turbine 16 and rotates the carrier 63-67 and the ring gear 65 to rotate in the same sense and at a lower speed. The pinions 71 are rotated by the sun gear 70 opposite to the turbine causing the pinions to revolve about the ring gear 65 in the same direction of rotation as the turbine. Because ring gear 65 isrotating in the same direction but at a lower speed than that of the sun gear 711, the carrier 7475 revolves within the ring gear 65 at an intermediate speed and in the same direction; that is, intermediate the speed of rotation of the sun gear Wand the ring gear 65. The member 75 is keyed to the output sleeve 76-.

For third speed or direct'drive through the gearing, the clutch 51 is engaged. Engagement of this clutch locks the ring gear 43 directly to the gearing input shaft 12 through the member 519. Thus, the sun gear 41), pinions 41, and ring gear 43 rotate in unison. This constrains the carrier 63-67, ring gear 65 and sun gear 70 also to rotate in unison-and there can be no rotation of the pinions 71 on their shafts 73 with the result that the carrier member 75 transmits the torque to the output sleeve 76 at the same speed and in the same direction as that of the rotation of'the shaft 12.

In low range the brake elements 9597 hold ring gear 65. The sun gear 76 turns at low speed and this is transmitted to the output sleeve 86.

In reverse the brake elements 1117-1118 hold the ring gear 81. The sun gear 71 rotates pinions 71 forward on their axes 73, which are initially held by the resistance of the output shaft 76, and the pinions cause the ring gear 65 and sun gear 68 to rotate backward, and since ring gear 81 is held stationary the carrier 833d, keyed to the output sleeve 76 drives the output sleeve 76 backward.

The cross shaft 90 extends toward opposite sides of the vehicle and only one side is shown in detail in FIG. 6, it being understood that the arrangement at the opposite side is identical.

The cross shaft is journalled in a pair of bearings as 1311', beyond which it extends as at 131. Keyed to each end portion 131 is a clutch hub 132. The clutch comprises multiple discs 133, the driving discs being splinedto the hub. 132 and the driven discs being splined to the flange portion 135 of a final drive shaft 136 which is adapted to receive a traction member or traction-driving member. In the case of a track laying vehicle, the trac-' tion member to be received by the final drive 1361s a form of sprocket for driving the track. Keyed or otherwise secured to the flange 135 as at 138 is a hydraulic cylinder 1411 within which is a piston 141 for engaging theclutch to connect the cross shaft 90 to the final drive member 136. Suitable springs 142 normally hold the? clutch discs 133 disengaged. The cylinder member 14t1' has an extending sleeve 143 to which is attached the driving member of a pump 144L for hydraulic medium, the pump being completed by a pump housing mernber 1td secured to the casing 1.

A brake construction involves a multiple disc brake structure 150, driving discs of which are splined to the flange 135, as indicated at 151, and driven discs of which are splined as at 152 to a fixed brake housing 153 fastenedto the housing 1. The brake structure is enclosed by a plate 154. This brake is arranged to be engaged by rotation of a cam ring 156, which also is a brake pressure plate. This is illustrated in FIGS. 2 and 3. The ring 156 has a plurality of circumferentially spaced angularor helical grooves 158. The brake housing 153 has a plurality of circumferentially spaced angular-or helical grooves 159. The grooves 158 and 159 match each other to'the brake housing, the balls serve to shift the ring 156 downwardly as FIG. 6 is viewed, to engage the brake 150.

Each of the several balls in their matching grooves'may be retained therein and enclosed by a plate 161.

As shown in FIG. 2, the brake ring 156 may be normally held retracted by a releasing spring 162. There is a brake on each side of the transmission and for manually operating each cam ring 156 there is a lever 163 'flll". crumed at 164 and fixed to a cam element 165 with a cam surface 166 and a' notch 167. Another lever 168, pivoted at 173 withinthe casing has a roller 169 for engaging the cam element 165. The lever 168 has a recess 1711 for receiving one end of the strut 171, the opposite; end'of which is positioned'in the recess 172 in one end of the cam ring 156. Normally, under the action of the spring 162. parts are in the position shown in FIG. 2' with the-roller 169' seated in the notch 167. When the lever 163 is rocked clockwise as FIG. 2 is'viewed, the cam surface 166 engages the roller, rocks the lever 168, causes the'strut to shift the cam ring 156 clockwise, The cam action of the balls in the recesses 158 and 159 shifts the cam ring 156 downwardly as FIG. 6 is viewed to engage the brake 154 This ground brake structure is confinedin a brake chamber 17 which has a sealing element 175;

As shown in FIG. 7 the two levers 163 are operable; by rods 176; One rodis connected to a link 177 and the other is connected to a link 178 and these links are connected to pivots 179 and 186 between their ends to link members 131 and 1823, which are in turn connected respectively to steering and brake levers 183' and 18 1. The opposite ends of the links 177 and 173 are pivoted as at 186, 137 to a rocker arm 1911 pivoted at 191 to the housing and keyed to a steering valve operating arm 192; the purpose of which will presently be seen. Projections 193 may strike the'housing 1 to limit the rocking action" of member 1911.

Associated with each ground brake is a valve to supply cooling oil to the brake discs (F16. 9). A lever 11 5' has onefend abutting the brake pressure plate 156 and its other end carrying a valve 197 urged by'a spring 196 to engage a seat 198, to close a vent passage 199 which leads to the intake of the brake cooling pump 2 02. Pas-' sage 199 communicates with thepassage 2% which is in communication with the brake chamber 174. Passage 1% may actually open into the interior of the crank case. While the actual construction is illustrated in FIG. 9, the diagrammatic illustration of the system, in FIG. 10, shows the valve 1517 in the form of a ball. This is merely for convenience. The brake chamber 174 may be open as shown at 2111 in FIG. 10 (not shown in FIG. 9) for the discharge of the cooling oil. In FIG. 10, the same reference characters are used for the right and-left ground brakes.

Brake Cooling Control The pump system for hydraulic medium is diagram-' matically illustrated in FIG. 10. There are four pumps for oil, 202', 21th, 211, all driven by the gear 8 which is connectedto the impeller 5 directly driven by the engine. There are two pumps 2112 for pumping cooling oil to the two ground brakes. One pump and its system may be described, the other being the same. For supplying oil to the lefthand brake, the pump has an inlet line 2115" communicating with the sump 2196, a pressure line 207 for conducting oil to the brake chamber and a branch inlet 2113 "which can be vented at'199'under control of valve 117': When the member 156 is retracted'by its spring 163, with' the ground brake disengaged, the cam ring risesas in F118. 9 to unseat the valve 197 to open the port 199. Therefore, the pump 2112, instead of drawing oil from thesump, merely pumps air through its inlet and through its outlet. Thus, in normal operation with' the ground brake released, the ground brake pump 202 is hotcalledupon to pump hydraulic liquid, reducing to area. in the crank case.

a minimum wear on the pump parts and saving power. When the brakeis applied the cam ring 156 shifts downwardly as FIG. 9 is viewed, which is a shift to the left, as the left hand ground brake, in FIG. 10, is viewed, and the valve member 197 closes the air bleed port 199. The pump then immediately draws oil from the sump and pumps it through the line 267 and clearance 267a (FIG. 9) through the ground brake chamber, cooling the discs and this oil is then discharged through the port 201.

Main Control Other pumps driven by the gear 8 are a main input pump 210 with an inlet in the sump 206, and an auxiliary pump 211 with its inletin what may be termed a scavenge This area is a location where some oil collects and so hte pump 211 removes the oil.

therefrom. The pump'211 has an outlet line 212, and the pump 211 is for lubricating the bevel gears 88 and 89, by

supplying a spray ring 213 (FIGS. and 6) adjacent the face of the gear 83. This is of circular form, interrupted only at the gear 89. A plate 214 closes the ring on the side adjacent the teeth of gear 88' and it is provided with a plurality of apertures 215 for the discharge of oil di rectly onto the teeth of the gear $8. Thus, these bevel ears are efficiently lubricated and cooled. The outlet line 212 is illustrated diagrammatically in FIG. 5 as communicating into the manifold 213 although its position has been modified in order to show it in thedrawing.

The left-hand, orwheel-driven pump, 144-1. has an inlet from the sump 2% and the right-hand output, or wheeldriven, pump is similar as shown in FIG. 10. Both the right and left-hand output pumpsand the main input, or engine-driven, pump 21%? connect into the main pressure line 220. One of the output pumps 144L and 144R pumps into the main pressure line when the vehicle is going forward and the other when the vehicle is backing. The action is controlled by a system of check valves. As indicated in FIG. 10, the vehicle may be considered as going forward and the pump ll iL is pumping into the main pressure line through check valve 221 while check valve 222 is closed. The pump 144R is not pumping and its check 223 is closed while check valve 224 isopen and the pump is circulating air or air with some oil therein, through the bypass 225. When the vehicle operates in reverse, pump 144R pumps oil into the main pressure line and 144L pumps air through the bypass 226.

This reverse pump arrangement supplies lubricating oil both when the vehicle is towed or pushed forward and backward with the engine not running. If the vehicle is towed backward the output pump 144R supplies sufficient oil to the system for keeping the parts lubricated. This arrangement is particularly adaptable and useful for military vehicles.

Steering Control The main pressure line has a branch 236 (FIG. 11) which extends to valves for controlling the right and left tion of a track'laying vehicle, and the action is coupled hand output clutches 133. Connecting into the left hand clutch control valve is a port 231 and leading therefrom is a line 232 which extends to the cylinder 140 (FIG. 6). Line 233 connects into the right-hand control valve and line 234 runs to the cylinder of right-hand output clutch. The'left-hand valve 239 is held normally against a center stop 235 by a spring 236 and it has a port 237 which normally connects the lines 231232.- The left-hand valve has an exhaust port 238. The right-hand valve 245 is similarly constructed with a port 240, spring 241 and an exhaust port 242. The valve controlling arm 192 lies between the two valve members. As FIG. 11 is viewed, if the arm 192 is swung counter-clockwise, the connection between the lines 231 and 232 is closed and 232 is opened to the exhaust 233. As a result the left-hand output clutch 153 will become disengaged. Movement of the arm 192' clockwise will, in a similar manner, cause the right-hand output clutch to become disengaged.

This action is employed in the steering and manipulawith thermanual controliof the r'ight and left-hand brakes,

the left-hand brake being shown at 150. The operator may apply both hands to the control levers 183184 (FIG. 7) and if the operator applies equal force to both control members, the manual brakes are applied. This may be done to stop the vehicle in a straight line of movement. To turn the vehicle, for example, to the left,

the operator applies more force to-the lever 184. This causes the double crank lever member 1% to rock on its axis 3.21 thus shifting arm 192 counter-clockwise to close off the oil under pressure to theleft hand output clutch. Thus, the brake 159 may be applied and the output clutch 133 disengaged, and the vehicle is turned to the left. The right-hand output clutch and the right-hand brake are similarly controlled by the right-hand valve.

Automatic Transmission Control lands 254, 255. The next higher position is for high range automatic operation of the transmission in second and third-speed ratios; the next higher position locks the transmission in second speed ratio; the next higherposition lock the transmission in the low speed ratio; the next higher position is for reverse. The valve body, is connected to a pressure line 260 for the second and high speed ratios, to the pressure line 261 for the second speed ratio only, to the pressure line 262 for the low speed ratio, and to the pressure line 263 for reverse. The body has a line 264 connecting to a lock-up clutch valve 375. A segment 25% and a spring-pressed detent 259 holds the valve member in a selected position.

Associated with the manual control valve is a speedresponsive downshift inhibitor in the form of a plunger 266 with a piston 267 which can be moved down by governor pressure in the cylinder 263 against the force of a return spring 269 far enough to engage a secondary spring 270.

This inhibitor can cooperate with a stop 271 having an abutment face 272 and an abutment face 273 to prevent downshift movement of the manual valve operator 258 when the car is moving above a predetermined speed, as will be explained. The chamber 274 of the manual valve has a discharge port controlled by check valve 2'75 and a small bleed port 275a not controlled by the check valve.

The main pressure regulator is indicated generally at 289 and the main pressure line 220 connects into a regulated pressure chamber 281 thereof. The pressure regulator valve includes a valve stem 282 urged to the right by spring 289. The stem includes a governor piston 283, a main regulating land or piston 284, a converter charging land 285 functioning in a converter charging port 286 and a maximum pressure land 2 87 functioning in a maximum pressure relief port 288. The regulated pressure chamber 281 has a pressure relief valve 2% discharging ultimately to the torque converter and has a passage 293 leading to a pressure-regulating chamber on the right of land 284, while the port 286 lies between the regulated pressure chamber 281 and a reduced pressure converter Iow governor pressure in the chamber between the large end of piston 2% and end wall 2%, as will be explained. Leading from the chamber 294 is a reduced pressure torque converter supply passage 380 provided with a relief valve 3t}! and also provided with a restricted converter supply port 3G2 leading to the converter inlet pas sage 3%. A second restricted passage fiddconnects the converter supply passage 30% with a cylinder of a converter pressure regulator valve. 7 I

As is known to those versed in the art, a circulation of oil is maintained in the converter particularly when it is used to transmit torque and the oil from the converter discharges into a passage 31% which leads to a converter flow valve 311 havingan exhaustvport 312. The flow valve 311 is urged by a spring 311a to close the inlet end of the conduit 394 and in this position it has port;-

313 and 314 which connect the converter discharge conduit 318 with the exhaust 312. i

In the converter discharge passagcrliltl is a pressure relief valve 315 which can connect to the discharge line 3%.

The line 3116 continues past the relief valve 301 into the" cylinder 3% which can dischargeto a cooler and lubricating lines through a port317 controlled by a head 1318 on the stern of a converter regulator and cooler bypass valve generally indicated at 32% which stem is urged to the left by a head 321 acted upon by liquid entering the cyl inder 3% and is normally urged to the right as FIG. 11 is viewed by a primarily acting coil spring 322 and a secondary spring 323 which backs up a headed member 324. This valve stem also has a head 327 operating in a port lying between a passage 316a and a lubricant passage 323 which leads directly to a transmission lubricant line 33%. This lubricant line has a pressure relief valve 331 to maintain a relatively low pressure therein. The line 316a continues around the head 287 and into line 31% where it enters the cooler 'which discharges into the lubricant line 330. There is a bypass 332 extending around the cooler which may be controlled by a valve 333..

For cont-rolling changes of ratio there is an output shaft driven governor, 34% (FIGS. 6, ll) which may be of known construction, such as the governor inFlG. of the Thompson US. Patent 2,204,872. The governor is rotated by shaft 336driven by worm gearh2 35won the output sleeve '76 (FIG. 6). A low speed valve 341 is urged out or to the left as FIG. 12 is seen by a relatively large centrifugal weight 342 and is urged in by the pres; sure on a large land 3454 of oil in passage G to which oil is admitted from passage 350, (connected to mainline 250) under the control of small land 343. The pressure in passage G is maintained as a function of governor speed jointly by the admission of oil from line 25% and exhaust of oil through passage 352 as is known. Likewise,a lower pressure at a given speed of. rotation is maintained in high speed passage G by high speed valve 345 urged outward by a small weight 346 and urged inward by pressure on head 348 maintained jointly by admission of oil from line 351 (connected to main line 259) and exhaust of oil through passage 353 both under control of land 347.

There is a throttle actuated valve 355 with a grooved valve stemfidd which can be urged down, as PKG. 11 is seen, by an arm 36'] fixed to the engine throttleshaft lidt through a loose or lost motion connection illustrated at 369. The stem 366 is urged up by a spring 37d. The pressure line G passes through this valve as shown to shift control valves to be described and to the downshiftim hibitor 251. Pressure line G also goes to the main pressure regulator valve to urge the head 28 3, and the head 2% to the left, tending to reduce main line pressure.

There is a converter lock-up clutch valve generally in dicated at 375, having a valve stem 3754:: which can be urged to the right by a piston 376 under the infiuenceor" control pressure, as will be explained. The stem 3755a has a piston 377 and a relatively largeland fifttlr and a relatively small land 381, all urged to the right by spring 378. The lock-up clutch release line 264 can conduct line pressure from the manual valve 252, when in reverse, to the space at the left of'piston 377 to prevent the engagement of the lock-up clutch, as willbe explained. The second and high speed pressure line 266 has a'branch 26th: which leadsinto the lock-up valve at the location of land 35% and is normally closed thereby. Leading from the lock -up clutch valve 355 is the line 13 in the converter output shaft 12, which extends to the cylinder 36 of the lock-up clutch. Thevalve has an exhaust port 379. Ex-

tending from the cylinder 30 of the lock-up clutch to the converter flow valve 311 is a line 3S3 which restricts fiow through the converter when the lock-up clutch is engaged, as will be explained.

The pressure line G passes around neck 385 in the throttle actuated valve 366 and thence to chamber 386 in the lock-up clutch valve 355 so as to act upon the piston 377 to open the valve and engage the clutch at high vehicle speed as will be explained. The line G also has a branch which passes into a chamber 387 in the clutch lockup valve to act upon the head 381 thereof.

There is a gear shift valve generally indicated at 396, having the valve member 391 urged closed, or to the right by springs 392 and it has a governor piston 393 adjacent a governor chamber 394. It also has a land 3% at the location where the line 26% enters the shift valve and a smaller land 3%, defining a governor (G pressure chamber.

The shift valve can be held closed to prevent upshifting of the planetary gearset by control pressure at the left of a piston 3%? in a third speed loch-out chamber 398 which can be supplied with oil at main line pressure by line 2 51 from chamber 274 of the manual valve 252 when in second speedposition marked 2 The pressure in line G tends to open the shift valve by acting upon the head 3%. The line G also extends into the throttle actuated valve on the underside of the head 399 thereof.

The line G extends to the throttle actuated valve and into the upshitt chamber 394 of the shift valve 3%.

There is a high clutch actuating line which connects into the shift valve between the two heads 3% and 3% and when the shift valve is open this line 4% fills the high clutch cylinder 47. From the high clutch cylinder 47 line 4&1 leads to a pressure-limiting valve 4 3161 for urging the loch-up clutch valve 375 closed with a limited force. The pressure-limiting valve has a valve stem with a head urged closed by a spring 483. The stem also has a head 4%- and a head idd. The limiting valve has a port 4-06 which leads from line dill into a cylinder 4%"? in which the piston 376 is disposed. Connected to the cylinder th? is a pressure-limiting chamber 4% disposed above land 4055; The pressure limiting valve has an eX-- haust port 4 M.

The pressure limiting valve is a regulator valve in which the pressure in chamber 4497 passes into chamber 463 and urges head 495 down against the force of spring 4493; Thus, an excessively high pressure in the chamber 4'37 causes the head 4% to close inlet port 4% and to open exhaust port 411% and the pressure in chamber 497 is thus limited by the force of spring 4%.

The line 4% also leads to a shuttle valve having a body 311 with a ball valve 412. therein. The line 22 for the low speed range also extends to the shuttle valve on the opposite side of the ball member 2-12. A passage 415 connects the interior of the shuttle valve with a second speed release chamber 416 in the cylinder 61 on the left side of the piston oil. The piston 6h is urged in the bandreleasing direction by a spring 417. A branch will: of the high clutch line 4% connects into a second release cylinder 425) in which there is a piston 4215 with a piston rod 422 extending through the end 423 of the cylinder 42%? to engage the piston head tilt. A spring 42d acts upon the piston head 321, v

- but is prevented by piston heads 2.54 and brakes which could establish drive through the gearing. The oil from the main inlet ,ing of the converter outlet regulator necessary, if the cooler becomes defective, disabled Operation 7 of Control Assume that the engine is idling with the manual valve in the position N shown in H6; ll which is neutral. The main input pump 2ltl'is pumping oil into the high pressure line 22% and its branches 230 and 250. The brake coolant pumps are operating but if the brakes are not applied the inlets to these pumps are opened so that the pumps'merely draw air. The scavenge pump 211 is operating for supplying cooling lubricant to the bevelled gears. The oil underv pressure flows to the manual valve,

255 from actuating any of the clutches or pump 2M9 passes into chamber 281 of the main pressure regulator valve 2250 and through passage 293 to the right side of the head 234. This urges the valve stem 282 to the left and, at a pressure determined by the spring 23%,

causes the head 235 to crack port 286 so that oil enters the chamber 294 and converter supply chamber 3%, from which a limited amount of oil may initially pass through the port 392 into the inlet 3% of the torque converter,

and dischargefrorn the'torque converter'outlet line ii the pressure acting on piston 2%, assisting spring 239 to increase pressure.

To drive the car in automatic range the operator shifts the manual control valve one notch upwardly into the H position for second and high speed ratios. The groove .257 now connects the pressureline with the line 269 which leads to the cylinder 61 for second speed apply piston as; it runs through the shift valve 3% and to the lock-up cltuch valve 3%. The oil under pressure flows to the chamber 61, shifts the piston 6t; to the left and contracts the second speed clutch band as on the member 45 and conditions the gearing to. transmit torque through the .second speed ratio. If the throttle is opened enough for through port's 313 and 314 to exhaust port 33.2. At this time the pressure in the converter may be relatively low and the rate of flow through the converter is minimized.

This depends on idling speed of the engine,viscosity of the oil, capacity of the pump 21% and leakage from the system. Ordinarily at idling speed, the pump 21% maintains normal converter pressure, as it must to assure lubrication of the planetary gears, as will be explained. As converter pressure becomes established in chamber 3% .by the main regulator valve 282, the pressure moves the converter flow valve 311 to the right, closing the converter outlet at port 31.3 and opening the communication between chamber 3% and the converter inlet 3%. The oilunder converter pressure also enters the cylinder 3% through restricted passage 365 and moves the converter regulator and by-pass valve 318 to the left opening port 317. Oil at converter pressure lifts the check valve 315 off its seat and flows through pipe 316 and open port 3-17 to the lubricating passage 3316:: from which it flows around land 287 of the main regulator valve and through the cooler to the lubricating line. It is obviously necessary for the converter regulator valve 318 to open port 317 inorder to supply any lubricating fluid to the various bearings and gearing, which must be kept lubricated whenever the engine is running, because shaft 12 and all the gears are turning.

It will be noted that the outlet for the converter is controlled by the pressure on the inlet side. With this arrangement undue pressure cannot be built up within the converter. Should the cooler become clogged, that is, tending to build up the pressure, the converter outlet regulator valve shifts further to the left due to the built up pressure in chamber 306 and the head 32'] will then open the passage 3116a to a bypass line' 3.23 which leads directly to the lubrication line 330; The normal maximumopenvalve is determiner by the spring pressed head 324. Clogging of the cooler will raise the pressure and then the converter outlet regu-' lator valve member will shift further to the left against the spring 323 thus opening the port 317. Thus the mechanom Wil continue to operate if for some reason the cooler is clogged or otherwise cut out of the system. Also, if or clogged the valve 333 maybe opened for bypassing the oil around the cooler through line 332.

Oil at main line pressure enters through line 295 into the chamber 7353s at the left end of the pressure regulator to urge the piston 2% to the right. The main pressure regulator valve member is thus urged in opposing directions, namely, by the oil under pressure back of piston 234 which tends to decrease line pressure and by the engine to develop sufficient torque we now have the vehicle moving and the governor valve is being rotated. When sutlicient car speed is attained, the low speed governor valve 341 has raised the pressure in the line G high enough to shift the lock-up clutch valve 375a to the left as FIG. 12. is viewed, which connects the pressure line asst; to the lock-up clutch line 13- so that the oil is'conducted to the lock-up clutch cylinder 3t andthe lock-up clutch begins to engage. The line 383 extends from the lock-up clutch cylinder 3% to the space in the cylinder 3%3a at the right of converter flow valve plunger 311, entering through port 383. As the lock-up clutch engages the converter fiow valve is shifted to the left, thus reducing supply of oil to the converter to the minimum flow of oil through port 362. This is done because the torque is now transmitted directly through the lock-up but this maintains a lower pressure in G than the pressure in the line G As the vehicle accelerates still more, increasing pressure in the lines G and G moves the shift valve 3%. to the left. Upon this occurrence the head 395 connects the line 260 to the line 4190 which leads to the high clutch cylinder 47 and begins to engage the clutch 51. From the cylinder 47 the line connects to the shuttle valve 411 holding ball valve 412 to the right so that the oil under pressure passes into the second speed release chamber 416. The oil from line 400 also passes through line 400a into an auxiliary release chamber 420 to act upon the piston 421. This causes the piston 60 to move to the right against the pressure in chamber 61 to begin disengagement of the second speed ratio brake band 46.

At the same time, that-is, during the shift from second to high, the lock-up clutch is disengaged and the cone verter restored to action. This occurs because line 401 conducts oil under pressure from line 400 to the pressure limiting valve 4tl1a in Which the oil flows between the heads 492 and 4M and through port 46-6 to establish in the chamber 497 a reduced or limited pressure, as explained above. This overcomes governor pressure and moves the valve stem 375a to the right, closing the connection between the pressure line 260 and the lock-up clutch pressure line 13 and opening the line 13 to the exhaust 379. This, of course, removes the pressure in line 383 so that the pressure is relieved from the converter flow valve 311 and the pressure in chamber 300 shifts the converter flow valve to the right to thus establish a Wide connection between chamber 300 and the converter inlet 304.

Therefore, it will be seen that during the shift the lock-up clutch is disengaged and torque, is transmitted through the converter and this softens the action of the shift in the releasing of one friction device and engaging of the other.

Bear in mind that at this stage of the operation, the torque converter is transmitting the torque. ther increase of speed, the pressure in the line G further increases to overcome the limited pressure in chamber 407 and shifts the clutch lock-up valve back to the left again to set the lock-up clutch and to reduce the flow of oil through the converter.

Upon fur- In a downshift from high to second the operation is just the reverse.'-'- Ascar speed drops the pressure in line G drops and the lock-up clutch valve is shifted to the right by pressure in chamber 407, to restore the converter to action. Further, reduced governor pressure also allows the shift valve 391 to shift back to the position shown in FIG. 11, thus cutting off supply of oil to the high clutch line 400 and venting clutch 47, chamber 497 and release chambers 416 and 42%) to disengage third speed and establish a second speed.

At'this point, it is well to note that the lock-up clutc valve has heads 380 and 331 of different size. Therefore, when this valve member has been opened, at a particular governor pressure, to establish a connection between line 260 and line 13, the greater force of the pressure on head 380 than on head 381 holds the valve open until the pressure in the line G is lower than the above certain pressure, which represents a lower speed. Thus, for' example, the lock-up clutch valve may open under pressure in line G representing fifteen miles an hour, but will not close until there is a vehicle deceleration to say 11 or 12 miles an hour. These figures are exemplary only. Likewise the shift valve 3H has different sized heads 395 and 396 so that once it is opened it remains open until there is a substantial drop in the pressure in lines G and G This, of course, means a drop in vehicle speed. a

.If it is desired to operate the vehicle constantly in the second speed ratio the manual valve 252 is placed in the position marked 2 in FIG. 11. This, merely opens the shift valve lock-out line 261 to the main line 250 and pressurizes the chamber 398 at the left end of the shift valveand prevents the valve from opening under any circumstances.

To operate in the low speedratio the operator shifts the manual valve to the L position of FIG. ll. This connects the main line 250 to the line 262 which leads to the low ratio cylinder It)? to engage the low brake. But, the second speed-brake band 46 must he released. For this purpose, line 362 extends to the shuttle valve 411, passes into the same shifting the ball 4-12 to the left to close the line 409 so that the high clutch cannot be set. The oil thus flows through the shuttle valve line 415 and into second speed release chamber 416. Since the piston 60 is unbalanced, because of the spring 417, the combined load of the spring and oil pressure in chamber 416 shifts the piston 69 to the right as FIG. 11 is viewed thus disengaging the low speed brake band.

To operate in reverse the manual valve is shifted upwardly another notch to the reverse position marked R. At this time the head 255 lies between the connections of the line 259 and the line 260 and thus closes the main pressure line 25% off from the chamber 274. Thus, there is-no pressure in lines 269, 261 or 262. These lines are vented through the check valve 275 and port 275a. At this time the head zss closes the port 259 and a connection is established from line 254 into line 263 for conducting oil to the reverse speed ratio brake cylinder 116. The inhibitor prevents the operator from manually downshifting at too high speed. For example, when operating in high speed ratio and at a high vehicle speed, the plunger 266 is shifted downwardly against both of-the springs 26? and 270 and'it blocks against the'face 272 to prevent shift to'second speed at such a high vehicle speed. When operating in locked second speed ratio the face 273 is in position to be blocked by the plunger 266 and thus a shift cannot be made to low speed ratio at too high a vehicle speed. The spring 269 acts on the plunger 266 at all times but when the pressure in the line G increases the head 267 picks up the auxiliary springs It will be noted that the line 264 extends from the chamber 274 of the manual valve to the lock-up clutch valve so as to act upon the head 377 in a direction reverse tothat of the action of the pressure in line G This helps release the lock-up clutch. For example, when operating in low the head 254 is in a position above the line 262. In shifting from low to second, the head 254 moves to a position between line 261 and line 2.62. and line 262 vents through the restricted port 275a and the check valve 275 with its larger port. This retards the bleeding pressure and the pressure is transferred to the lowlock-up clutch valve to help shift it to release the lock-up clutch and restore the converter for the shift from low to second.

The arrangement of having pressure from the governor valve in line G active upon the main pressure regulator valve, serves to reduce the main line pressure with increase of speed in normal operation tothus save expenditure of power. At-a relatively high speed of operation the pressure in line G v increases and is active upon the piston 2% and due to the difierent-sized piston areas the main line pressure on the left sideof the pressure regulator valve member is relieved. Thus, the gov,- ernor pressure on the head 283 urges the valve member I to the left with greater effect than before so that the main line pressure is reduced as speed increases.

There is an overcontrol or kick-down. effected by the throttle actuated valve 355. The shaft sea turns with the throttle controlling mechanism, and after predetermined opening of the throttle, the key engages the end of the slot 369 and molds the lever 357 clockwise as PEG. 12 is seen. The key and slot is merely diagrammatic of any suitable lost play connection. This pushes the valve member 366 against its spring and closes the connection in line G between the governor valve and the lock-up clutch chambers 386 and 387 and the space on the right of land 3% of the shift valve 3%. The neck 33S establishes a connection between the line G through port G and said chambers 336, 387 and space behind land 3%. By thus reducing the pressure effective to hold the clutch lock-up valve open the lock-up clutch valve can be closed by the spring 378 and pressure in chamber dill. Therefore, by way of example, if the vehicle be operating, in the high speed ratio, with the lock-up clutch engaged and the throttle is then widely opened, the lock-up clutch is released, restoring transmission of t rque through the torque converter without any change in the speed range in the gearing of the transmission. This increases the over-all torque ratio of the transmission to provide accelera-tion in an emergency, for example. "if thereafter car speed increases enough, increased governor pressure in line G acting in chambers 3 56 and 387 can open the lockup clutch valve to set the lock-up clutch again.

T o briefly reiterate the overall action, the operator can make a selection in the operation of the manual valve. When a shift is made from one speed ratio to another and during the course of the shift the lock-up clutch disengages and the torque converter is restored to action. The

shift is thus made with torque transmitted through the torque converter which softens and smooths the function. Thereafter the torque demand on the transmission may be reduced, as indicated by increasing car speed, and the lock-up clutch engages. Then, too, as is stated above when operating with the lock-up clutch engaged with a widely open throttle, the lock-up clutch can be manually disengaged and the torque converter restored to action to provide increased torque.

The steering of the vehicle is accomplished in a simple manner by combined and cooperative control of the vehicle brakes and the output clutches. By pulling evenly on the two levers T83 and 184 the brakes are applied. By pulling unevenly the driving clutches for the final drive members are selectively released or caused to slip. The double coned clutches soften the clutching action in making a gear shift. While operating constantly, the engine operated pumps for the oooling'of the brakes, merely draw air when brakes are not applied thus resulting in saving of power. Moreover, the main line pressure is savin expenditure of power.

I claim: 7 I

1. A transmission comprising in combination a driving shaft connected to the impeller of a hydrodynamic torquetransmitting, device which has a turbine connecti'ole through step-ratio gearing to a driven shaft, a lock-up clutch for connecting the turbine to the impeller,

means responsive to increase in speed of rotation of the driven shaft for setting the clutch, means responsive to further increase of speed of the driven shaft for decreas ing the torque ratio of the gearing, means responsive to initiation of change oftorque ratio of the gearing for releasing the clutch, and meansresponsive to still further increase in speed of the output shaft for re-engaging the lock-up clutch.

2. A transmission comprising in combination adriving shaft-connected to the impeller of a hydrodynamic torquetransmitting' device which has a turbine connectible through step-ratio gearing to a driven shaft, a lock-up clutch for connecting the turbine to the impeller, a source of pressure fluid, a pressure-operated lock-up motor which when pressurized'engages the clutch, a lockup valve whichvwhen open pressurizes the lock-up motor and when closed vents the lock-up motor, means for establishing one torque ratio in the gearing, a pressure-operated gear shift motor which when pressurized establishes a second torque ratio in the gearing, a gear shift valve which when open pressurizes the gear shift motor and when closed vents the shift motor, means responsive to one predetermined speed of rotation of-the driven shaft for opening the shift'valve, means responsive to opening of the shift valve for closing the clutch valve, and means responsive to a second predetermined speed of rotation of the driven shaft for opening the clutch valve.

3. A transmission comprising in combination a driving shaft connected to the impeller of a hydrodynamic torquetransmitting device which has a turbine connectible through step-ratio gearing to a driven shaft, a lock-up clutch for connecting the turbine to the impeller, a source of pressure fluid, a pressure-operated lock-up motor which when pressurized. engages the clutch, a lock-up valve which when open pressurizes the lock-up motor and when closed vents the lock-up motor, means for establishing one torque ratio in the gearing, a pressure-operated gear shift motor which when pressurized establishes a second torque ratio in the gearing, a gear shift valve which when open pressurizes the gear shift motor and when closed vents the shift motor, means responsive to one predetermined speed of rotation of the driven shaft for closing the lock-up valve, means responsive to a second predetermined speed of rotation of the driven shaft for closing the shift'valve and means responsive to closing of the shift valve for opening the lock-up valve.

4. A transmission comprising in combination a driving shaft connected to the impeller of a hydrodynamic torquetransmitting device which' has a turbine connectible through step-ratio gearing to a driven shaft, a lock-up clutch for connecting the turbine to the impeller, a source of pressure fluid, a pressure-operated lock-up motor which when pressurized engages the clutch, a normally closed lock-up valve which when open pressurizes the lock-up motor and when closed vents the lock-up motor, means for establishing one torque ratio in the gearing, a pressure-operated gear shift motor which when pressurized establishes a second torque ratio in the gearing, a normally closed gear shift valve which when open prcssurizes the gearshift motor and when closed vents the shift motor, a governor which maintains a fiuid pressure which is a measure of the speed of rotation of the driven shaft, a first fluid pressure valve motor connected to the governor which opens the lock-up valve at one speed of rotation of the driven shaft, and a second fluid pressure valve motor connected to the governor which opens the shift valve-at a different speed of rotation.

5. A transmission comprising incombination a driving shaftconnected to the impeller of ahydrodynamic torquetransmitting device which has a turbine connectible through step-ratio gearing to a driven shaft, a lock-up clutch for connecting the turbine to the impeller, a source of pressure fluid, a pressure-operated lock-up motor which when pressurized engages the clutch, a

normally closed lock-up valve which when open pressurizes the lock-up motor and when closed vents the lock-up motor, means for establishing one torque ratio in the gearing, a pressure-operated gear shift motor which when pressurized establishes a second torque ratio in the gearing, a normally closed gear shift valve which when open pressurizes the gear shift motor and when closed vents the shift motor, a governor which maintains a fluid pressure which is a measure of the speed of rotation of the driven shaft, a first fluid pressure valve motor connected to the governor which opens the lock-up valve at one speed of rotation of the driven shaft, a second fluid pressure valve motor connected to the governor which opens the shift valve at a different speed of rotation, a third fluid pressure valve motor which when pressurized urges the lock-up valve to close, and means responsive to opening of the shift valve for pressurizing the third valve motor.

6. A transmission comprising in combination a driving shaft connected to the impeller of a hydrodynamic torquetransmitting device which has a turbine connectible through step-ratio gearing to a driven shaft, a lock-up clutch for connecting the turbine to the impeller, a source of fluid under pressure, means for regulating the pressure of the source, a pressure-operated locloup motor which when connected to the source engages the clutch, a normally closed lock-up valve which when open connects the lock-up motor to the source and when closed disconnects the lock-up motor from the source and vents the lock-up motor, means for establishing one torque ratio in the gearing, a pressure-operated gear shift motor which when connected to the source establishes a second torque ratio in the gearing, a normally closed gear shift valve which when open connects the gear shift motor to the source and when closed disconnects the gear shift motor from the sourceand vents the shift motor, a governor including a reducing valve which maintains a pressure less than the pressure of the source, which reduced pressure is a measure of the speed of rotation of the driven shaft, a first fluid pressure valve motor connected to the governor which at one predetermined speed of rotation of the driven shaft opens the lock-up valve, a second fluid pressure valve motor connected to the governor which at another predetermined speed of rotation opens the shift valve, a third fluid pressure valve motor which when pressurized urges the lock-up valve to close with a force proportional to its pressure, means responsive to opening of the shift' valve for connecting the third valve motor to the source, and pressure limiting means for reducing below the pressure of the source the maximum pressure in the third valve motor.

7. A transmission comprising in combination a driving shaft connected to the impeller of a hydrodynamic torquetransmitting device which has a turbine connectible through step-ra tio gearing to a driven shaft, a -lock-up clutch for connecting the turbine to the impeller, a source of fluid under pressure, means for regulating the pressure of the source, a pressure-operated lock-up motor which when connected to the source engages the clutch, a normally closed lock-up valve which when open connects the lock-up motor to the source and when closed disconnects the lock-up motor from the source and vents the lock-up motor, means for establishing one torque ratio in the gearing, a pressure-operated gear shift motor which when connected to the source establishes a second torque ratio in the gearing, a normally closed gear shift valve which when open connects the gear shift motor to the source, and when closed disconnects the gear shift motor from the source and vents the shift motor, a governor including a reducing valve which maintains a pressure less than the pressure of the source, which reduced pressure is a measure of the speed of rotation of the driven shaft, a first fluid pressure valve motor connected to the governor which at one redetermined speed of rotation of the driven shaft urges the lock-up valve to open with a force proportional to governor pressure, a second fluid pressure valve motor connected to the governor which at another predetermined speed of rotation opens the shift valve, a third fluid pressure valve motor which when pressurized urges the lock-up valve to close with a force less than the maximum governor pressure and means responsive to opening of the shift valve for connecting the third valve motor to the source.

8. A transmission comprising in combination a driving shaft connected to torque-multiplying mechanism which drives a driven shaft at different torque ratios, torque ratio-changing control means which normally tends to increase the torque ratio of the multiplying mechanism, a governor connected to the driven shaft which maintains a first source of relatively high fluid pressure which is a measure of the speed of rotation of the driven shaft and maintains a second source of relatively low fluid pressure which also is a measure of the speed of rotation of the driven shaft, means for conducting fluid from the high pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission at a predetermined speed of rotation of the driven shaft, and means for interrupting the supply of high pressure governor fluid and conducting fluid from the low pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission.

9. A transmission comprising in combination a driving shaft connected to torque-multiplying mechanism which drives a driven shaft at different torque ratios, torque ratio-changing control means which normally tends to increase the torque ratio of the multiplying mechanism, a governor connected to the driven shaft which maintains a first source of relatively high fluid pressure which is a measure of the speed of rotation of the driven shaft and maintains a second source of relatively low fluid pressure which also is a measure of the speed of rotation of the driven shaft, means for conducting fluid from the high pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission at a predetermined speed of rotation of the driven shaft, and manually operable means for interrupting the supply of high pressure governor fluid and conducting fluid from the low pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission.

l0. A transmission comprising in combination an engine connected to torque-multiplying mechanism which drives a driven shaft at different torque ratios, torque ratiochanging control means which normally tends to increase the torque ratio of the multiplying mechanism, a governor connected to the driven shaft which maintains a first source of relatively high fluid pressure which is a measure of the speed of rotation of the driven shaft and maintains a second source of relatively low fluid pressure which also is a measure of the speed of rotation of the driven shaft, means for conducting fluid from the high pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission at a predetermined speed of rotation of the driven shaft, and means responsive to a predetermined torque demand on the engine for interrupting the supply of high pressure governor fluid and conducting fluid from the low pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission.

11. A transmission comprising in combination a driving shaft connected to torque-multiplying mechanism which drives a driven shaft at different torque ratios,

torque ratio-changing control means which normally tends to increase the torque ratio of the multiplying mechanism, a governor connected to the driven shaft which maintains a first source of relatively high fluid pressure which is a measure of the speed of rotation of the driven shaft and maintains a second source of relatively low fluid pressure which also is a measure of the speed of rotation of the driven shaft, means for conducting fluid from the high pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission at a predetermined speed of rotation of the driven shaft and means for interrupting the supply of high pressure governor fluid and effect an increase in the torque ratio of the transmission at one speed of rotation of the driven shaft, said last-mentioned means also conducting fluid from the low pressure governor source to the ratio-changing control means to decrease the torque ratio of the transmission to effect a decrease in the torque ratio of the transmission at a higher speed of rotation of the driven shaft.

12. A transmission comprising in combination a driving member connected to the impeller of a hydrodynamic torque-transmitting device having a turbine connected to an output member, a lock-up clutch which can connect the impeller to the turbine, a pump driven by the driving member for circulating liquid through the torquetransmitting device, means for selectively setting and releasing the lock-up clutch, a slow flow passage constantly connecting the pump to the torque-transmitting device, and a normally closed fast flow passage which can connect the pump to the torque-transmitting device, said transmission including fluid pressure means responsive to the pressure in the slow flow passage for opening the fast flow passage upon occurrence of a predetermined high pressure in the slow flow passage.

13. A transmission comprising in combination a driving member connected to the impeller of a hydrodynamic torque-transmitting device having a turbine connected to an output member, a lock-up clutch which can connect the impeller to the turbine, a pump driven by the driving member for circulating liquid through the torquetransmitting device, means for selectively setting and releasing the lock-up clutch, a slow flow passage constantly connecting the pump to the torque-transmitting device, a normally closed fast flow passage which can connect the pump to the torque-transmitting device, said transmission including fluid pressure means responsive to the pressure in the slow flow passage for opening the fast flow passage upon occurrence of a predetermined high pressure in the slow flow passage, and means responsive to setting the lock-up clutch for overcoming the fluid pressure opening means and closing the fast flow passage.

14. A transmission comprising in combination a driving member connected to the impeller of a hydrodynamic torque-transmitting device having a turbine connected to an output member, a lock-up clutch which can connect the impeller to the turbine, a pump driven by the driving member for circulating liquid through the torque-transmitting device, means for selectively setting and releasing the lock-up clutch, a slow flow passage constantly connecting the pump to the torque-transmitting device, a fast flow passage which can connect the pump to the torquetransmitting device, a fluid pressure motor for setting the lock-up clutch, a value which can open and close the fast flow passage, means normally closing the valve, said transmission including fluid pressure means responsive to the pressure in the slow flow passage for opening the fast flow passage upon occurrence of a predetermined high pressure in the slow flow passage, said transmission also including a second fluid pressure means for closing the valve, and fluid connection between the second fluid pressure means and the lock-up motor for closing the valve when the clutch is set.

15. A transmission comprising in combination a driving member connected to the impeller of a hydrodynamic torque-transmitting device having a turbine connected to an output member, a lock-up clutch which can connect theimpeller to the turbine, 21 fluid pressure motor for setting the lock-up clutch, a pump driven by the driving member for supplying liquid under pressure, means for regulating the pressure of the pump, means for selectively connecting the pump to the lock-up motor and disconnecting it therefrom, means including a supply space connected to the pump and an inlet passage connected to the torque-transmitting device for conducting liquid from the pump to the torque-transmitting device, means for maintaining in the supply space a pressure less than the regulated pressure of the pump, and control means for selectively opening and closing the inlet passage, said control means including means constantly tending to close the inlet passage, and including first fluid pressure means responsive to the pressure in the supply space for opening the inlet passage, and including second fluid pressure means for closing the inlet passage against the pressure of said first fluid pressure means, and including a fluid connection between the second fluid pressure means and the lock-up motor for closing the inlet when the lock-up clutch is set.

16. In a transmission, the combination of a drive shaft, a driven shaft, means for providing a first power train between said shafts including a hydrodynamic coupling device having a bladed driving element and a bladed driven element within a fluid housing, means for providing a second alternate power train between said shafts including a clutch and a fluid pressure operated piston within said housing acting against the fluid pressure in the housing to engage said clutch, means for circulating fluid through said hydrodynamic coupling device including a fluid inlet to said fluid housing, means for maintaining the fluid in said housing at a certain pressure when said first power train is completed, and means for reducing the pressure in said housing when said second power train is completed and including means forming a restriction in the fluid inlet of said hydrodynamic coupling device, means forming a second relatively unrestricted passage in parallel with said restriction, and a piston subject to the pressure of the fluid applied to said piston for said clutch for closing said parallel passage when clutch engaging fluid pressure is applied to said clutch piston.

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Tuck et al Apr. 11, 1961 

16. IN A TRANSMISSION, THE COMBINATION OF A DRIVE SHAFT, A DRIVEN SHAFT, MEANS FOR PROVIDING A FIRST POWER TRAIN BETWEEN SAID SHAFTS INCLUDING A HYDRODYNAMIC COUPLING DEVICE HAVING A BLADED DRIVING ELEMENT AND A BLADED DRIVEN ELEMENT WITHIN A FLUID HOUSING, MEANS FOR PROVIDING A SECOND ALTERNATE POWER TRAIN BETWEEN SAID SHAFTS INCLUDING A CLUTCH AND A FLUID PRESSURE OPERATED PISTON WITHIN SAID HOUSING ACTING AGAINST THE FLUID PRESSURE IN THE HOUSING TO ENGAGE SAID CLUTCH, MEANS FOR CIRCULATING FLUID THROUGH SAID HYDRODYNAMIC COUPLING DEVICE INCLUDING A FLUID INLET TO SAID FLUID HOUSING, MEANS FOR MAINTAINING THE FLUID IN SAID HOUSING AT A CERTAIN PRESSURE WHEN SAID FIRST POWER TRAIN IS COMPLETED, AND MEANS FOR REDUCING THE PRESSURE IN SAID HOUSING WHEN SAID SECOND POWER TRAIN IS COMPLETED AND INCLUDING MEANS FORMING A RESTRICTION IN THE FLUID INLET OF SAID HYDRODYNAMIC COUPLING DEVICE, MEANS FORMING A SECOND RELATIVELY UNRESTRICTED PASSAGE IN PARALLEL WITH SAID RESTRICTION, AND A PISTON SUBJECT TO THE PRESSURE OF THE FLUID APPLIED TO SAID PISTON FOR SAID CLUTCH FOR CLOSING SAID PARALLEL PASSAGE WHEN CLUTCH ENGAGING FLUID PRESSURE IS APPLIED TO SAID CLUTCH PISTON. 